<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>
<body>
<!---->
<div id="header"></div>
<script>
  new Vue({         //实例
    el:header,        //挂载点
    template:'<h2>Hello World {{msg}}</h2>',      //模板
    data:{
      msg:"hah"
    },
  })
</script>
</body>
</html>
